Current wireless access points (APs) allow for simultaneous operation in different bands (e.g., one in the 2.4 GHz band and one in the 5 GHz band). However, previously available APs experience highly degraded performance when two co-located radios operate within the same band (e.g., two radios operating in the 5 GHz band). The reason for this is that when one radio is transmitting in close proximity to another radio that is receiving, packet reception is degraded by interference and throughput scaling is not achieved.
Radio hardware is designed to operate over a wide frequency range in a particular band (e.g., channels in the 5 GHz band). As such, receivers have gain and signal detection circuitry over the entire band. If one co-located and same-band radio transmits a high power signal, that signal can overdrive the other radio when it is receiving due to close physical and spectral proximity of the radios. As a result, the receiving radio may lose any packets that the radio is currently decoding. This results in a loss of potential throughput and a “sharing” of the air time between the radios.
The second issue that limits the same band operation of co-located radios is excessive transmitter noise floor that exists in integrated circuits manufactured using currently available silicon processing technology. Currently available integrated circuits and associated hardware have limited out-of-band noise transmission using limited filtering capabilities which reduce baseband noise. The transmitter noise floor affects the entire band of operation and can limit the signal-to-noise-plus-interference-ratio (SINR) of the radios and in turn limit the range of radios. This noise can increase the received signal's SINR greater than what that packet modulation can accept, and as a result, the received packet may be lost.
To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements disclosed in one embodiment may be beneficially utilized on other embodiments without specific recitation.